SA Dermatology Definitions

Question 1

Macule

Answer 1

Circumcised, non-palpable spot, change in the color of the skin

Question 2

Papule

Answer 2

Small, elevation of the skin (1 cm), palpable solid mass

Question 3

Pustule

Answer 3

Small, circumcised elevation of the epidermis filled with pus

Question 4

Vesicle

Answer 4

Sharply circumcised elevation of the epidermis filled with clear fluid

Question 5

Wheal

Answer 5

Sharply circumcised, raised lesion with edema
Appears and disappears within minutes or hours

Question 6

Nodule

Answer 6

Circumcised, solid elevation >1 cm in diameter, extends into the deeper layers of the skin

Question 7

Tumor

Answer 7

A large mass that may involve any structure skin or SQ tissue

Question 8

Alopecia

Answer 8

Loss of hair, partial to complete

Question 9

Scale

Answer 9

Accumulation of loose fragments of the horny layer of the skin

Question 10

Crust

Answer 10

Formed when dry exudate, serum, pus, blood, cells, scales, or medication adhere to the surface

Question 11

Comedo

Answer 11

Dilated hair follicle filled with cornified cells and sebaceous material

Question 12

Epidermal collarette

Answer 12

Special type of scale arranged in a circular rim of loose keratin flakes or peeling keratin

Question 13

Hyperpigmentation

Answer 13

Increased epidermal +/- dermal melanin

Question 14

Excoriation

Answer 14

Erosions or ulcers caused by scratching, biting, or rubbing

Question 15

Erosion

Answer 15

Shallow epidermal defect that doesn’t penetrate the basal laminar zone
Heals without scaring

Question 16

Ulcer

Answer 16

Break in the continuity of the epidermis with exposure of the dermis

Question 17

Fissure

Answer 17

Linear cleavage into the epidermis or through the epidermis into the dermis, caused by disease or injury

Question 18

Lichenification

Answer 18

Thickening and hardening of the skin, exaggeration of the superficial skin margins

Question 19

Layers of the skin

Answer 19

Epidermis (top)
Dermis
Subcutaneous tissue

Question 20

Epidermis

Answer 20

Keratinocytes (major cell type)
Melanocytes (produce melanin)
Langerhans (Ag-presenting cells)

Question 21

Layers of the epidermis

Answer 21

Basal layer (cell division)
Spinous layer (desmosomes, cell differentiation)
Granular layer (keratohyalin granules)
Horny layer/ S. Corneum (barrier/ cornified layer)

Question 22

______________ is only found in the footpads and nasal planum only

Answer 22

Clear layer (S. Lucidum)

Question 23

Dermoepidermal Junction

Answer 23

Separates epidermis from the dermis
Layers: basal keratinocytes, lamina lucida (proteins), lamina dense (type 4 collagen), sub lamina densa (anchoring fibrils)

Question 24

Dermis

Answer 24

Supports and nourishes the epidermis
Complex matrix of fibers (collagen, elastin, reticulin, muscle)
Ground substance (glycosaminoglycans)
Innervation from myelinated spinal nerves

Question 25

Cells found in the dermis

Answer 25

Fibroblasts (produce collagen) Mast cells (binds IgE, Ag attaches, mast dell degranulation- type 1 hypersensitivity) Histocyte (macrophages)

Question 26

Subcutaneous tissue

Answer 26

Fat with CT, BVs and nerves Fat storage, heat insulation and body contour (shape)

Question 27

Epidermal appendages

Answer 27

Sebaceous glands (secrete sebum) Sweat glands Hair follicle and hair

Question 28

Sweat glands

Answer 28

Apocrine for thermoregulation Eccrine found on footpads

Question 29

Hair follicle growth phases

Answer 29

Anagen (growth)- breeds that needing grooming in this phase Catagen (intermediate) Telogen (resting)

Question 30

Primary lesions

Answer 30

Macule/ patch Vesicle/ bulla Tumor/cyst Wheal Nodule Pustule Plaque or papule

Question 31

Secondary lesions

Answer 31

Epidermal collarette Scar Excoriation Erosion/ ulcer Fissure Lichenification Callus

Question 32

Lesions that may be primary or secondary

Answer 32

Alopecia Scale Crust Follicular casts Comedo Pigmentary abnormalities